This invention relates to an electro-optic crystal modulator holder, and more particularly to a holder for a solid crystal such as CdTe or GaAs for modulating a laser beam.
Several United States patents are of interest in showing the state of the art relating to crystal modulators and crystal mounts. U.S. Pat. No. 3,322,485 to Williams shows an electro-optical device having conductive leads attached to conductive films layered on spaced plates. U.S. Pat. No. 3,914,021 to Nishimura teaches a liquid crystal device including a frame of molded plastic for supporting conductive plates. U.S. Pat. No. 3,958,862 to Scibor-Rylski discloses a modulator comprising a block of electro-optical material and electrodes on one face of the block. U.S. Pat. No. 4,054,362 to Baues shows a modulator including a liquid or solid crystal disposed on a substrate, the crystal being coated with a dielectricmaterial. U.S. Pat. Nos. 4,214,819 to Pohl et al and 4,334,734 to Hareng et al teach electro-optical modulators having a liquid crystal layer sandwiched between crossed polarizers.
A number of modulator drive waveforms of interest for laser radar applications require short rise and fall times. Cavity dumped waveforms may require voltage fall times of less than 50 nanoseconds for a modulator charged to 2700 v. Minimization of fall time requires reducing both the intrinsic and stray modulator capacitance to a minimum. If in addition the modulator is required to transmit high average powers (10-200 watts) it is also necessary to provide adequate modulator cooling to minimize thermally-induced mode instabilities and even modulator damage. Other properties which are desirable in a modulator holder include high voltage isolation (greater that or equal to 3.5 kv for 5 mm CdTe crystal) of the modulator, low RF loss for RF modulator waveforms, stress-free electrical contacting of the modulator crystal, and acoustic damping of the modulator crystal.